Semilunar valves

Definition

Semilunar valves are specialized heart valves located at the bases of the large arteries (the aorta and the pulmonary artery) that leave the heart, preventing blood from flowing back into the heart ventricles after it is pumped out. They are named for their crescent moon-like shape.

Related terms

Aorta:

The largest artery in the body that carries oxygen-rich blood from the left ventricle to be distributed throughout the body.

Pulmonary Artery:

The artery carrying deoxygenated blood from the right ventricle to the lungs for oxygenation.

Ventricles:

The two lower chambers of the heart responsible for pumping blood out to the lungs and rest of the body